code: def test_rand_amp():
      from speechbrain.augment.time_domain import RandAmp
  
      rand_amp = RandAmp(amp_low=0, amp_high=0)
      signal = torch.rand(4, 500)
      output = rand_amp(signal)
      assert output.mean().mean(0) == 0
  
file_path: speechbrain/tests/unittests/test_augment.py
imports: import os
  import torch
  import torchaudio
  from speechbrain.dataio.dataio import write_audio
label_desc: Use image node_id 8 for calling a global function with example usage: test_rand_amp() without return types